<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <title>第一次作业</title>
    <style>
        div {
            width: 100px;
            height: 100px;
            background: rgb(0, 217, 255);
            position: relative;
            animation: AL 4s infinite;
        }

        @keyframes AL {
            0% {
                background: rgb(0, 217, 255);
                left: 0px;
                top: 0px;
            }

            25% {
                background: rgb(238, 255, 0);
                left: 1000px;
                top: 0px;
            }

            50% {
                background: rgb(255, 51, 0);
                left: 1000px;
                top: 1000px;
            }

            75% {
                background: rgb(238, 255, 0);
                left: 0px;
                top: 1000px;
            }

            100% {
                background: rgb(0, 217, 255);
                left: 0px;
                top: 0px;
            }
        }
    </style>
</head>
<body>
    <div></div>
</body>

</html>